Part nationalised lenders RBS and NatWest are slashing charges paid by customers for unauthorised overdrafts or exceeding agreed overdraft limits.From 1 October, accounts will be charged £5 for returning a cheque, direct debit or standing order, down from £38 at the moment.The penalty for paying an item when an account is overdrawn has been halved to £15.'We thought it was time to move this particular customer concern forward by cutting our charges,' said the new CEO of the UK Retail Bank, Brian Hartzer.'As it relates to past charges we are awaiting the outcome of the industry-wide bank charges test case.'Today's announcement comes ahead of a decision of the new Supreme Court on whether or not the Office of Fair Trading (OFT) can regulate these charges.Figures out last week, revealed that Britain's financial services industry was bombarded with more than 9m complaints between 2006 and 2008. The volume of complaints rose by 5.7% over the three year period to 1.48m, according to statistics published by the Financial Services Authority (FSA). Customers were most likely to moan about overcharging and poor service.